and prison records represent conditions among a lower socioeconomic status segment of
society.
United States’ Insolation
Calcium and vitamin D are two chemical elements required throughout life for
healthy bone and teeth formation; however, their abundance are most critical during
younger ages (Wardlaw, Hampl, and Divilestro, 2004, pp. 394-396; Tortolani et al, 2002,
p. 60). Calcium generally comes from dairy products, and vitamin D in not dietary but is
produced by the synthesis of cholesterol and sunlight in the epidermises’ stratum
granulosum (Holick, 2007 video; Holick, 2004a, pp. 363-364; Nesby-O’dell, 2002, p.
187; Loomis, 1967, p. 501; Norman, 1998, p. 1108; Holick, 2007). Greater direct
sunlight (insolation) produces more vitamin D, and vitamin D is related to adult terminal
statures (Xiong et al, 2005, pp. 228, 230-231; X-ZLiu et al, 2003; Ginsburg et al 1998;
Uitterlinden et al, 2004).1 After the circulatory system contains sufficient amounts of
vitamin Dand to avoid vitamin D toxicity, vitamin D production is restricted within the
stratum granulosum and residual vitamin D is broken down into inert matter (Holick et al,
1981, pp. 591-592; Jablonski, 2006, p. 62; Holick, 2001, p. 20; Holick, 2004a, p. 363).
This self-limiting vitamin D effect may account for white stature variation with
insolation, because at North American latitudes whites are close to the natural threshold
where vitamin D production is curtailed (Jablonski, 2006, p. 62; Carson, 2009, pp. 150
and 154). At the opposite extreme, insufficient vitamin D has been linked to rickets,
1 Carson (2009, pp. 150 and 154) demonstrates that 19th statures were related to various factors, including
the primary source of vitamin D production (insolation).